>> lift the pots from the hardscape to insure good drainage
True! maybe a square of gardware cloth or three layers of window screening. Or thin strips of wood.
If I think the pot is staying too wet, I raise the pot up several inches on something with a pierced or grooved surface and set a strip cotton flannel under one or more drain holes. I drape the flannel down from that surface and let it hang down as much farther as possible. The flannel must touch the soil mix through the drainage hole.
Now capillary attraction PLUS gravity will pull water out of the bottom of the pot and flow it away downhill. Prevent perched water and peat-moss-soup.
I learned that plus my pine bark fetish from Al / Tapla, the Guru of gritty container mixes. But Al teaches that it is better to have really well-draining mix, than to play games with wicks.
And I always remind myself that drainage not only allows water to get out, it allows air to get in. Deep pots probably need side holes in addition to bottom holes (to encourage gas exchange).
>> It doesn't take long for soil in a container to go sour when you use soil.
I agree! Besides getting water-logged, pudding-ed, anaerobic or acidic fermentation, soil can retain too much salt from chemical fertilizers or manure.
With really perfect drainage, each watering can be heavy enough to fill all air spaces for a few seconds, then drain right out the bottom again, leaving behind only a small amount of water. Flush every molecule of old gas out, and drawing new, fresh air back in! Out with the old, in with the new!
My theory is that "Earth Boxes" get away with a puddle of water in the bottom of the pot by having many air holes along the side, PLUS a big air chamber between water level and the colander that supports the soil mix. Air diffuses in and keeps the air chamber fresh, which then keeps all of the soil aerated. (Also, the points of contact between soil mix and water ("wicks") are smallish in a well-designed Earth Box. The number of roots that drown and die each time the water rises is small.
